LVS is an abbreviation of Linux (an open source operating system) Virtual Server, which is a virtual server cluster system. The LVS mainly includes a load balancer and back-end servers. The load balancer is a front-end part of the cluster system, and configured to send a request from a client to the back-end server. The back-end servers are a group of servers performing the request of the client.
Currently, the load balancer generally checks health of the back-end server via Keepalived program (a keep-alive program).
However, when the keep-alive program checks health of the back-end server, a health checking packet is sent to the back-end server directly through an internal network IP address of the load balancer, such that it is hard to determine whether the client and the back-end server are normal, and thus a large traffic loss or mistakenly rejecting the back-end server may be caused.